Constructed Wetlands - Wikipedia.org

Jolu and Star Lake mines mentioned in a discussion on constructed and natural wetlands as a method for disposing of tailings:

"Mine water - ammonia

Constructed wetlands have been used to remove ammonia from mine drainage. In Ontario, Canada, drainage from the polishing pond at the Campbell Mine flows by gravity through a 9.3 hectare surface flow constructed wetland during the ice-free season.[20] Ammonia is removed by approximately 95% on inflows of up to 15,000 cubic metres (530,000 cu ft)/day during the summer months, while removal rates decrease to 50-70% removal during cold months. This ammonia was oxidized to nitrate, which was immediately and quantitatively removed in the wetland. Surprisingly, and contrary to Reed (see above), anoxic conditions were not necessary for nitrate removal, which occurred as readily on leaf and detritus biofilm as it did in sediments.[citation needed] Other contaminants, including copper, are also removed in the wetland, such that the final discharge is fully detoxified. Campbell became one of the first gold mines in Ontario to produce a completely non-toxic discharge, as determined by acute and chronic toxicity tests. At the Ranger Uranium Mine, in Australia, ammonia is removed in "enhanced" natural wetlands (rather than fully engineered constructed wetlands), along with manganese, uranium and other metals.

Other mines use natural or constructed wetlands to remove nitrogenous compounds from contaminated mine water, including cyanide (at the Jolu and Star Lake Mines, using natural muskeg and wetlands) and nitrate (demonstrated at the Quinsam Coal Mine). Wetlands were also proposed to remove nitrogenous compounds (present as blasting residues) from diamond mines in Northern Canada. However, land application is equally effective and is easier to implement than a constructed wetland."

http://en.wikipedia.org/wiki/Constructed_wetland

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